Determination of the genetic, molecular, and biochemical basis of the Arabidopsis thaliana thiamin auxotroph th1

Ajjawi, Imad; Tsegaye, Yoseph; Shintani, David K.

doi:10.1016/j.abb.2006.11.011

Cited by 54 publications

(67 citation statements)

References 30 publications

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“…In Arabidopsis thaliana, three enzymes participate together in the synthesize of thiamin monophosphate (TMP), namely, TH1 (Ajjawi et al, 2007a), THI1 (Belanger et al, 1995;Machado et al, 1996), and the TPP riboswitch-regulated THIC (Bocobza et al, 2007;Raschke et al, 2007;Wachter et al, 2007;Kong et al, 2008). Unlike in prokaryotes where TMP can be directly converted into TPP (Begley et al, 1999), in Arabidopsis, TMP is subsequently dephosphorylated into thiamin (Komeda et al, 1988), which is then pyrophosphorylated into TPP by the thiamin pyrophosphokinases (TPKs), namely, TPK1 and TPK2 (Ajjawi et al, 2007b).…”

Section: Introductionmentioning

confidence: 99%

“…TPP is the active form of thiamin and is also the most abundant intracellular form of this vitamin in yeast (Schweingruber et al, 1991), plants (Ajjawi et al, 2007a), and animal tissues (Rindi and De Giuseppel, 1961). It is an essential coenzyme for the enzyme complexes pyruvate dehydrogenase (PDH) and 2-oxoglutarate dehydrogenase (2-OGDH) of the tricarboxylic acid (TCA) cycle and for the a-ketose transketolase (TK) homodimer of the pentose phosphate pathway (PPP; Frank et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

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Orchestration of Thiamin Biosynthesis and Central Metabolism by Combined Action of the Thiamin Pyrophosphate Riboswitch and the Circadian Clock in Arabidopsis

et al. 2013

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Riboswitches are natural RNA elements that posttranscriptionally regulate gene expression by binding small molecules and thereby autonomously control intracellular levels of these metabolites. Although riboswitch-based mechanisms have been examined extensively, the integration of their activity with global physiology and metabolism has been largely overlooked. Here, we explored the regulation of thiamin biosynthesis and the consequences of thiamin pyrophosphate riboswitch deficiency on metabolism in Arabidopsis thaliana. Our results show that thiamin biosynthesis is largely regulated by the circadian clock via the activity of the THIAMIN C SYNTHASE (THIC) promoter, while the riboswitch located at the 39 untranslated region of this gene controls overall thiamin biosynthesis. Surprisingly, the results also indicate that the rate of thiamin biosynthesis directs the activity of thiamin-requiring enzymes and consecutively determines the rate of carbohydrate oxidation via the tricarboxylic acid cycle and pentose-phosphate pathway. Our model suggests that in Arabidopsis, the THIC promoter and the thiamin-pyrophosphate riboswitch act simultaneously to tightly regulate thiamin biosynthesis in a circadian manner and consequently sense and control vital points of core cellular metabolism.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Orchestration of Thiamin Biosynthesis and Central Metabolism by Combined Action of the Thiamin Pyrophosphate Riboswitch and the Circadian Clock in Arabidopsis

et al. 2013

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“…This suggests that plants may utilize a biosynthetic pathway that is similar to that of microorganisms. Two genes involved in thiamine biosynthesis have so far been cloned and characterized in Arabidopsis [28][29][30]. The first one is THI1, which is involved in thiazole synthesis.…”

Section: Introductionmentioning

confidence: 99%

“…Also, THI1 possesses a signal peptide at its N terminus, which targets the THI1 protein to mitochondria and chloroplasts [31,32]. The second is the Arabidopsis thaliana HMPPK/TMPPase gene (At1g22940) [30,33]. The HMPPK/TMPPase protein is localized in the chloroplast compartment and has two enzymatic activities -namely as a TMP-PPase at the C terminus and a HMP-P kinase at the N terminus [30,33].…”

Section: Introductionmentioning

confidence: 99%

“…The second is the Arabidopsis thaliana HMPPK/TMPPase gene (At1g22940) [30,33]. The HMPPK/TMPPase protein is localized in the chloroplast compartment and has two enzymatic activities -namely as a TMP-PPase at the C terminus and a HMP-P kinase at the N terminus [30,33]. The arrangement of the two functional domains in one protein results in the coordinated synthesis of the two enzymes for thiamine biosynthesis.…”

Section: Introductionmentioning

confidence: 99%

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AtTHIC, a gene involved in thiamine biosynthesis in Arabidopsis thaliana

Kong

Zhu

et al. 2008

Cell Res

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Thiamine (vitamin B1) is an essential compound for organisms. It contains a pyrimidine ring structure and a thiazole ring structure. These two moieties of thiamine are synthesized independently and then coupled together. Here we report the molecular characterization of AtTHIC, which is involved in thiamine biosynthesis in Arabidopsis. AtTHIC is similar to Escherichia coli ThiC, which is involved in pyrimidine biosynthesis in prokaryotes. Heterologous expression of AtTHIC could functionally complement the thiC knock-out mutant of E. coli. Downregulation of AtTHIC expression by T-DNA insertion at its promoter region resulted in a drastic reduction of thiamine content in plants and the knock-down mutant thic1 showed albino (white leaves) and lethal phenotypes under the normal culture conditions. The thic1 mutant could be rescued by supplementation of thiamine and its defect functions could be complemented by expression of AtTHIC cDNA. Transient expression analysis revealed that the AtTHIC protein targets plastids and chloroplasts. AtTHIC was strongly expressed in leaves, flowers and siliques and the transcription of AtTHIC was downregulated by extrinsic thiamine. In conclusion, AtTHIC is a gene involved in pyrimidine synthesis in the thiamine biosynthesis pathway of Arabidopsis, and our results provide some new clues for elucidating the pathway of thiamine biosynthesis in plants.

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Plant Kingdom as Source of Vitamins

Hennebelle¹

2020

Handbook of Dietary Phytochemicals

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A vitamin is an organic substance necessary, in small quantities, for the correct functioning of the metabolism of a living organism. It is an essential nutrient because this substance cannot be synthesized in sufficient quantity by this organism and thus must be provided through the food intake. Each organism has specific needs: a molecule can be a vitamin for one species and not be it for another. It is the case for example of Vitamin C. Some vitamins are water-soluble compounds, including all vitamin Bs (B1, B2, B3, B5, B6, B7, B9, B12) and vitamin C. Others are fat-soluble compounds and encompass vitamins A, D, E, and K. In this chapter, we have chosen to provide an overview of recent literature data only about vitamins provided exclusively or significantly by plant food, in particular vitamins A (as provitaminic carotenoids), B1, B9, C, E, and K1. Vitamins provided by animal food, such as vitamin D or vitamin B12, will be not discussed in this chapter.

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Determination of the genetic, molecular, and biochemical basis of the Arabidopsis thaliana thiamin auxotroph th1

Cited by 54 publications

References 30 publications

Orchestration of Thiamin Biosynthesis and Central Metabolism by Combined Action of the Thiamin Pyrophosphate Riboswitch and the Circadian Clock in Arabidopsis

Orchestration of Thiamin Biosynthesis and Central Metabolism by Combined Action of the Thiamin Pyrophosphate Riboswitch and the Circadian Clock in Arabidopsis

AtTHIC, a gene involved in thiamine biosynthesis in Arabidopsis thaliana

Plant Kingdom as Source of Vitamins

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